21 replies to this topic

[Petes.one]

I have a pair of matched 1 1/2 inch HIF4 carbs which came from a mid seventies MGB. With a change to more appropriate needles is there any reason why they would not do the deed on a 1275? The motor will be bored to 1360 and running a RE13 cam, with 1.5 ratio and flowed MG Metro head. I see reports of minis performing well with twin HIF38s, but those are almost impossible to find in this part of the world. I'm unsure what manifold to use - the MGB uses the log version with a carb angle of 20 degrees, while the mini and Metro carb angles are about 16 degrees. Given the built in float chamber I imagine the angle is not nearly as critical as it is for the HS carbs. I can have the MGB log shortened and modified to suit as the port end diameters are not too large at about 1.35 inches. A Maniflow would be nice, but I doubt that Father Christmas is that generous! Any helpful comments would be much appreciated.

[The Matt]

One thing I would suggest is contacting Burlen, they are very good with carbs/manifolds/linkages etc. They also have a good website >>>>> CLICK HERE <<<<<

[Dan]

Any cars you have seen running twin HIF38s must be using some kind of horrible bodged linkage as to my knowledge there were never any right handed HIF38 carbs produced. So you have to use two left handed units and invent some linkage magic. Not the best solution. A pair of HIF4s is the way to go if you want twin 1.5" HIFs as you suggest, these are obviously available in both right and left hand designs. A couple of people on here are running twin HIF4s and they are very happy with them I think. Mostly they just use a twin HS4 manifold I believe, the Minispares one can be drilled and tapped for the other two mounting bolts on each carb as the flange is left complete and not trimmed down around the shape of the carb mouth I think. I'm not familiar with the cam you describe but I think that twin 1.5"s might be a little restrictive on your planned engine. You should size the carbs based on the planned power output obviously, not knowing exactly what power figure you are aiming at I can't be sure but I'm guessing at the high 90s / low 100s. The chart below is a rough guide to carb sizing from Mr Calver Esquire and looking at it I think you might be better with twin 1.75" HS carbs.

[Dog]

Dan,

AFAIK, these are Twin 38's Suited for a Mini, these are NOT bodged in anyway! its how they came out of the factory. (but not on a Mini)

These I am going to rebuild, with the later HIF38 dashpot, which AFAIK, have ball bearings inside to make it smoother? this then will make my twin HIF38's better than HIF4... aparantly.


So heres a piccy of them

[fikus01]

that looks cool, what did they come off??

[Dog]

MGB orginally....

They are awesome, much better than HS or H carbs, due to float chamber being on the bottom, means you can do harder cornering, without starving any carb of fuel!....

This is what they are like 75% built, I need to find out where the hoses etc go yet...

[minivanman]

*toddles off to search ebay*

[Dog]

*toddles off to search ebay*

Good luck, those cost me £150 posted Took me about 3 months to find them via forums... as I can't stand ebay!

[Puddings]

I have twins 1 1/2" on mine and it pulls 120 on the rollers.

PS get rid of those K&N's and get a ITG with stub stacks they are much better

[fikus01]

jsut the stubstacks!! nothing wrong with cone filters especuially k+n's!!

[Dog]

Don't worry Puddings, I going put some Speedwell staks on eventully, I've also got a custom manifold I want to fit, but I need a weber box to fit it, something I havn't done to my Mini yet.... (oh nuts......)

[fikus01]

biggest webber box u can find is a good idea!! lots of room for the carbs to breathe!!

[Dog]

ahh but the problem I have, is I have custom dash, thats moved the standard 2 clock setup, into the Middle, so I need to see what sort of room I have... I have bought a Battary box to fit into the hole...

[fikus01]

mine i made myself and it goes from the wiper motor to the clutch cylinder

[Dog]

Nice!
If I never had to worry about my dash, I'd make the whole dash area into a air box...
But thats not going to happen on this Shell! So a battary box will do